<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box {
      width: 500px;
      background-color: pink;
      overflow: hidden;
    }

    .box .one {
      float: left;
      background-color: plum;
      height: 100px;
      width: 100px;
    }

    .footer {
      width: 400px;
      height: 100px;
      background-color: black;
    }
  </style>
</head>
<body>
  <div class="box">
    <div class="one"></div>
    <div class="two"></div>
    <div></div>
  </div>
  <div class="footer"></div>
</body>
</html>